Carbon or arc lamp



L. B. SPINNEY CARBON OR ARC LAMP April 28, 1931.

Filed July 16, 1928 Patented Apr. 28, 1931 UNHTE STATES PATENT OFFICE LOUIS B. SPINNEY, 0F AMES, IOWA, ASSIGNOR T0 IOWA STATE COLLEGE OF AGRICUL- TURAL AND MECHANICAL ARTS, 0F AMES, IOWA, A CORPORATION 0F IOWA CARBON ARC LAMP Application filed July 1G,

The principal object of this invention is to provide an arc or carbon lamp that when once adjusted requires no further attention or complicated mechanism to maintain the carbon rods or pencils in correct distance from each other.

A further object of this invention is to provide a portable arc lamp of high actinic value that burns the carbon pencils down 'i evenly and uniformly regardless of he type of electrical current used.

A still further object of this invention is to provide a carbon lamp that is easily adjusted to hold carbon pencils of various diameters and one that permits the easy placement or removal of the pencils in the lamp.

A still further object of this invention is to provide a carbon lamp capable of holding a plurality of carbon pencils side by side,

^ spaced apart and parallel with each other.

A still further obj ect of this invention is to provide a carbon or arc lamp that is easily and readily adjustable relative to the distance of the carbon pencils from each other.

A still further object of this invention is t0 provide a carbon or arc lamp that is economical in manufacture and endurable in use.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, pointed out in my claims and i" illustrated in the accompanying drawings,

in which:

Fig. 1 is a top plan view of my invention designed to hold two carbon pencils and be energized by an alternating electrical current.

Fig. 2 is a side view of my invention to be used with an alternating electrical current and shows the two carbon pencils held in proper operating position on the base of the device.

Fig. 3 is a side sectional view taken on line 3--8 of Fig. 1 and more fully illustrates the adjusting features of the device. v

Fig. l is a top plan view of my invention 1923. Serial No. 293,179.

showing the construction used when a direct electrical current is employed.

F ig. 5 is an enlarged perspective view of the bearing and carbon pencil supporting member used in the construction shown in Fig. 4.

VFig. 6 is a top pian view of still a different construction of my lamp when a S-phase current is employed for operating the device.

Arc or carbon lamps have been found indispensable where great intense light value is demanded. Perhaps they are most benefcial to civilization in the therapeutic and photographic arts. However, they have been heretofore unreasonably expensive and beyond the linancial reach of many due to the complicated automatic mechanism necessary to feed the carbon pencils and keep them in proper distance apart at all times. I have overcome these disadvantages will be apparent to those skilled in the art.

I have used the numeral 10 to designate the iiXed base portion used in all the designs shown in the drawings, which may be made of any suitable nonconductive material such as formica. In Fig. 1, this base 10 has a shallow trough 1l in its top extending completely across the base. Resting in this trough are the two movable base portions, 12 and 13, respectively. These last mentioned members may be made of b ass or other suitable conductive material. Integra-Hy formed on the end of each of the movable bases adjacent each other are aws 14 into which the carbon pencil 15 to be held is placed. 'Io secure a carbon pencil in a set of these aws, it is merely necessary to tighten the cap screw 16 that passes through one jaw and is threaded in the opposite jaw. To remove the carbon pencil from either set of jaws, the screw 16 should be loosened, thereby allowing the j awa to move away from each other and release the carbon rod or pencil from their grasp. It should here be noted that these jaws are each curved near their end portion to more successfully embrace and hold the carbon pencil. Each of these movable base members is slidably and adjustably secured in the trough 11 by having a longitudinal slot 17 in its length and through which a cap screw 18 2 Leos passes. Each ot these cap screws is threaded into the base 1() and has a washer 19 between its head and the top of the movable base through which it passes as shown in Fig. 8. By this arrangement the two carbon pencils will be held longitudinally adjacent each other as shown in Fig. 2, and the distance between them may be adj usted by sliding the movable bases in the trough 11 toward or away from each other.Y Then the desired space between the pencils 15 is obtained the cap screws 18 should be tightened, thereby preventing any displacement ot the movable bases in the trough.

I have used the numeral 2() to designate an electrical contact point in the form of a cap screw on each of the movable base members. Secured to these two contact points are the negative and positive electrical lead wires 21 and 22 respectively. It is recommended that the above described construction be used when the electric power used is ot alternating current, as with such a current there is no tendency for the carbon arc pencil on the positive side to pass over with the arc of light and build up on the negative carbon arc pencil. With alternating current the two carbon pencils will burn down evenly and maintain uniform distance between their free ends. The voltage used will depend much upon the size and purpose of the lamp. It a small lamp is used and the electric current at hand is the usual one hundred and ten volt, a resistance in series with the lamp should be 1 used, or a direct short circuit across the carbons will occur and cause the fusing or the house fuses. To start the arc across the two free ends ot the pencils, a carbon pencil or other conductive article at hand is placed across the tree ends ot the pencils and slowly drawn away thereby starting the arc. It the .t is not struclr the carbon arc pencils snould be moved nearer one another by adjusting the movable bases. The complete lamp may be turned or placed in any pt "1 tion without danger of the are jumping across the space between the pencils at a point not at the tree ends ot the two pencils. lllhen the carbon arc pencils have burned down to the jaws 14, they should be removed and new pencils inserted in the two sets of jaws.

In Fig. 4 is illustrated the construction recommended when a direct electrical current is used. In this arrangement, the base l() not only has the trough 11, but second trough 23 passing at right anglesl across the trough 11. In the trough 11 are the two movable base members 24 and which are exact duplicates of the movable base members 12 and 1?,- shnvn in Fig. 1. The two movable bases and 25 each have a set of jaws 2G, a jaw tightening screw 2'?, and a slot (not shown) tor adjusting purposes. Passing through each slot is a cap screw 28 having its threaded end threaded into the base mem- ,eso

ber 10. The numeral 29 designates a washer between the head of each cap screw 2S and the top of the movable base member. On each of the movable base members and 25 is a contact point 30 and 31 respectively. It should here be noted that these two movablebase members are considerable distance apart. In the trough 23 is a third movable base member 32 having its end 33 adjacent the center or the liXed base 1G concave to properly' embrace and support one side of a carbon arc pencil. This third movable base has a vertical longitudinal slot 34. Passing through the washer 36 on top of the third movable base member, the slot 84 and threaded into the liXed base 1() is the cap screw By this construction the base 32 is slidably and adjustably secured in the trough 23. Permanently secured in the other end of the trough 23 by the screw 37 is the bearing member 38 having the vertical and longitudinal notch 39. In each side of this notch is a slot 40. Slidably mounted in this notch 39 is the carbon pencil engaging member 41 having the two hey members 42 integrally formed thereon and engaging the two slots respectively. 'I'he forward end ot this pencil engaging member is concave for successfully engaging and supporting one side of a carbon arc pencil and is designated by the numeral 43.

Threaded longitudinally in the bearing member 38, entering the notch 39 and capable of engaging the bach portion of the carbon engaging member 41, is an adjusting screw this construction a carbon arc pencil in y be placed between the ends 33 and 43 and if; tightening the screw 44 the member 41 fill be pushed forwardly thereby rigidly nolcing the carbon pencil against removal from the two ends 33 and 43. The numeral 45 designates la Contact point on the third movable base member 32. It a carbon arc iencil is placed in each ot the two sets ot jaws 26, the device will be holding three carbon arc pencils, spaced apart in row formation .and parallel with each other. The distance between any one ot these pencils to another may be adjusted, as herebeiore explained. It has been found that when a direct current is used, the positive carbon arc pencil will burn approximately twice as fast as the negative carbon arc pencil. I theretore attach the positive side ot the electrical current to the contact points 30 and 31, and 4the negative side to the contact point 45, thereby providing two positive carbon arc pencils to one negative carbon arc pencil, and all of the carbon pencils will burn down unii'ormally and evenly.

In Fig. 6 I show the construction recommended when a three phase circuit is used. In this view are three troughs 4G, 47, and 48 in the top of the base 10 extending radially from a common center and equal distance apart. In each trough is a movable base member 4:9 which is an eXact duplicate of the movable base member' 12 shown in Fig. l. Each of these movable base members 49 have a set of jaws 50, a jaW tightening screw 5l and a longitudinal slot (not shown). They are each slidably mounted in their respective trough by having a cap screw 52 passing through the washer 53, the longitudinal slot in their length and threaded into the bottom of the trough in which they rest.

I have designated the contact points on each of these movable base members by the numerals 54, 55, and 56 respectively. These three contact points are designed to be in electrical contact with the three contact points of an electric generator respectively. By this construction three carbon arc pencils may be secured in upright position in the device, each of equal distance from the other two, as is desired when a three phase circuit is used.

Any desired lamp shade may be used and it will be found that a very pleasing light will be obtained suitable for all therapeutic purposes. It the device is to be use in photography orwhere it is desired that the arc emit more light falling in the ultra-violet region of the spectrum, the carbon pencils should be soaked in ferrie chloride or uranium nitrate solution, or impregnated with other materials which will give an arc rich in the desired wave lengths.

The principal advantage of any one of the before mentioned constructions is that the 1 carbon pencils will be held parallel to each other with their free ends adjacent to each other, thereby burning down continuously and evenly without any further adjustment of the mechanism.

Some changes may be made in the construction and arrangement of my improved carbon or arc lamp Without departing from the real spirit and purpose of my invention and it is my intention to cover by my claims any modilied forms of structure or use of mechanical equivalents which may be reasonably in-4 cluded within their scope.

I claim:

1. In a. device of the class described, a iixed base member, a trough extendingr in a straight lin-e formed in said base member, two movable base members in said trough, and a means for securing a carbon arc pencil to each of said movable base members; said parts being so arranged that When said base members are moved relative to each other, the longitudinal axes of the two carbon arc pencils will not be changed relative to each other.

2. In a device of the class described, a iixed flat top base member, a plurality of movable base members slidably and adjustably secured on the top of said base member, and a means for securing a carbon arc pencil to each of said movable base members; said parts being so arranged that when any one oi said movable base members are moved relative to any other movable base member, the longitudinal axes of all of the carbon are pencils held by said base members will not be changed relative to each other.

3. In a device of the class described, a iXed base member, a trough extending in a straight line formed in said base member, a plurality of movable base members slidably and adj ustably secured in said trough, and a means for securing a carbon are pencil to each of said movable base members; said parts being so arranged that when any one of said movable base members are moved relative to any other movable base member, the longitudinal axes of all ot the carbon arc pencils held by said base members will not be changed relative to each other.

fl. In a device ot' the class described, a base member, a plurality ot base members secured to said .tirst base member, a pair of curved jaws on each of' said last mentioned base members designed to engage and support a carbon arc pencil, and screw in each pair oi jaws for bringing and holding the same to gether.

5. In a device of the class described, a base member, a trough in said base member, a sec-- ond trough extending across the lirst trough at right angles thereto, a means for holdinga carbon arc pencil in said last mentioned trough, a movable base member on each side of said last mentioned trough and in said first trough, a set of jaws designed to hold a carbon arc pencil formed on each movable base member and adjacent the last mentioned trough, and a means for adjusting said movable base members in said trough.

G. In a device of the class described, a l'iXed base member, a trough in said base member, a movable base member adjustably secured in said trough, a concave end formed on said movable base member designed to engage and support one side of a carbon are pencil, a bearing member secured in said trough, a notch in the end of said bearing member adjacent said movable base member, a carbon arc pencil engaging member slidably mounted in said notch, a concave end formed on said engaging member designed to engage and support one side of a carbon arc pencil, and a screw threaded into said bearing member and engaging said pencil engaging member.

7. In a carbon arc pencil holder, a fixed base member, a trough in said base member, a movable base member adjustably secured in said trough, a concave end formed on said movable base member, a bearing member secured in said trough, a notch in the end ot said bearing member adjacent said movable base member, longitudinal slots in the side of said notch, an engaging member slidablv mounted in said notch, keys formed on sai-d engaging member designed to enter and en- Cir gage said slots respectively, and an adjusting screw threaded into said bearing member, entering said notch and capable of engaging the back portion of said engaging member for forcing said engaging member against a carbon arc pencil placed Vbetween said engaging member and movable base member.

8. In a device of the class described, a base member, a plurality of troughs formed in said base member extending in a straight line and in a common plane relative to each other, a plurality of movable base members slidably and adjustably secured in said troughs, and a means for holding a carbon arc pencil on each of saidniovable base members; said parts being so arranged that when any one of said movable base members are moved relative to any other movable base member, the longitudinal aXes of all of the carbon arc pencils held by said base members will notl be chang-ed relative to each other.

9. In a device of the class described, a iiat topped base member, two movable base members on said fiat top of said base member, and means for rigidly securing a carbon arc pencil to each of said movable base members and parallel with each other; said base members being so arranged that when they are moved relativevto each other, the parallel relation of said carbon arc pencils will not be changed.

LOUIS B. SPINNEY. 

